Apparatus for treating vascular diseases



Jan. 28, F RQENSCH APPARATUS FOR TREATING VASCULAR DISEASES Filed July14, 1938 W W a h mm 1501 2250/7 Patented Jan. 28, 1941 UNITED STATESPATENT QFFiCE APPARATUS FOR TREATING VASCULAR DISEASES 5 Claims.

This invention relates to the treatment of peripheral vascular diseasesand refers particularly to instrumentalities for producing anintermittent venous hyperemia.

Without resorting to the sesquipedalian language of medical science andwithout attempting to state the scientific and somewhat theoretic-a1explanation of how the production of intermittent venous hyperemia actsto produce beneficial results, it is desired to note that considerableresearch has been devoted to this therapeutic and that while variousopinions have been expressed, it is generally accorded highly beneficialfor the treatment of peripheral vascular diseases and especiallyobstructive vascular diseases. But the apparatuses heretofore availablefor effecting this treatment have been inadequate and objectionable.

In some of the devices heretofore in use for producing intermittenthyperemia, the limb to be treated was alternately subjected to anegative and a positive pressure through the application of suction on aboot encasing the limb.

Other methods employed an inflatable cuff secured about the limb to betreated and means to inflate it and thereby effect venous constriction.But in all past expedients, there has always existed the very seriouspossibility of applying either too high a suction or too great apressure on the limb.

Usually, either suction or pressure pumps were used; and unless theywere carefully controlled and regulated, the patient was in seriousdanger, to say nothing of the extreme pain to which he might besubjected.

This invention, therefore, has as one of its objects to provideinstrumentalities for producing a desirable intermittent hyperemia bymeans of air pressure, but in such a manner that the extent of thepressure is positively limited and incapable of exceeding apredetermined maximum.

It is also an object of this invention to provide an apparatus of thecharacter described which is absolutely safe in the hands of a noviceand which does not entail the attendance of a skilled technician.

Another object of this invention is to provide an apparatus of thecharacter described, which is entirely automatic in its operation and inwhich the frequency of the cycles and the duration of their individualsteps is readily adjustable.

It is also an object of this invention to provide an instrumentality ofthe character described, which not only applies intermittent venousconstriction upon the limb being treated, but also concurrently liftsand lowers the limb to afford mild exercise and permit the utilizationof postural effects upon the blood flow.

With the above and other objects in view which will appear as thedescription proceeds, this invention resides in the novel construction,combination and arrangement of parts substantially as hereinafterdescribed, and more particularly defined by the appended claims, itbeing understood that such changes in the precise embodiment of theherein disclosed invention may be made as come within the scope of theclaims.

The accompanying drawing illustrates one complete example of thephysical embodiment of the invention constructed according to the bestmode so far devised for the practical application of the principlesthereof, and in which:

Figure 1 is a side view of an apparatus constructed in accordance withthis invention illustrating its manner of use and in which parts arebroken away and in section; and

Figure 2 is a cross sectional view taken through Fi ure l on the planeof the line 2-2.

Referring now particularly to the accompanying drawing, in which likenumerals indicate like parts, the numeral 5 designates a conventionalinflatable and which is adapted to be strapped about the thigh of apatients leg, as illustrated.

As particularly shown in Figure 2, this cuff is in the form of a tube,preferably of rubber or other similar material, into which air is forcedirough an inlet nipple 6. Air under pressure is supplied to the cuffthrough a tube or hose 1 attached to the nipple t and leading from thebottom of an upright cylinder 8.

The cylinder 8 is preferably mounted in a portable cabinet 9 whichhouses and supports the entire equipment, with the exception of the cuff5, so that the apparatus may be readily moved about and located adjacentto the patients bed.

Reciprocable in the cylinder is a piston Ill. The piston iii of its ownweight augmented by a stack of removable weights l I descends by gravityto compress the air in the cylinder and inflate the cuff 5 with apressure determined solely by the total weight of the piston.

The fact that the pressure which it is able to exert upon the thighthrough. the inflatable cuif is positively limited and predetermined bythe weight of the piston is an important advantage of the presentinvention.

To enable the piston to be retracted after a complete descent or apartial descent depending upon the desired duration for the venousconstriction, a check valve I2 is mounted in the hot- III tom thereofwhich opens upon an upstroke of the piston.

During the pressure cycle the Weighted piston of the pressure cylindermoves only far enough to compress the confined air in the cylinder,connecting tube and cuff to the desired degree which is determined bythe total weight of the piston. When this point is reached, the descentof the piston is halted, unless a leak in the pressure system permitsfurther descent. In this case, the piston continues its downwardmovement but without increasing the pressure in the cuff,

At the completion of the pressure cycle, the piston is caused to moveupwardly in the cylinder. In consequence to the upward movement of thepiston, the confined air expands to reduce the pressure in the cuff.Thus, the piston in its upward movement reduces the pressure in thesystem to slightly below atmospheric; and when such a condition isreached, the check valve I2 opens to allow air from the outside to enterthe cylinder.

The retraction of the piston is eifected by an automatically operatingmechanism which con sists preferably of a reversible electric motor I3driving a drum M on which a tape or cable l5 connected to the piston iswound.

Where a reversible electric motor is used as described, its rotation inone direction winds up the tape Hi to retract the piston or lift it tothe top of the cylinder and a reverse operation of the motor releasesthe piston for gravitational descent.

The operation of the motor I3 is controlled by suitable timing switches(not shown), mounted in a housing It. The specific manner in which thesetiming switches function to control the forward and reverse operation ofthe motor [3 and the time at which such operation takes place need notbe described, for this mechanism is conventional and well known; sufficeit to say that the mechanism is readily adjustable to enable thefrequency of the cycles and their duration to be adjusted to suit anyparticular need.

A main switch I? is preferably mounted on the outside of the portablecabinet to control the con nection of the electric control and drivinginstrumentalities with a source of current which may be conductedthereto by a flexible cord 18.

As illustrated, the nipple 6 has a branch leading therefrom for theattachment of another hose or tube l9 which leads to a pressure gauge 20preferably mounted on the cabinet in a position to be readily visible.The gauge illustrated is of the mercury type and accurately registersthe pressure applied on the limb.

While this pressure may be any amount within a wide range as determinedby the weight of the piston, it being appreciated that the number ofindividual weights ll may be increased or decreased so that the pressuremay be set to suit any requirement, in ordinary instances a pressure of80 mm. of mercury is employed. For adding or removing weights 5 i, thecabinet has a door 2| affording access to the piston.

It is also desired to point out that the duration of the pressureapplied may range from a matter of seconds to minutes and that,likewise, the frequency of the cycles is variable within wide limitsranging from seconds to minutes. r

In addition to periodically producing hyperemia in the limb beingtreated, it is desirable to concurrently lift the limb and lower it sothat the benefits of postural effect upon the blood flow can beutilized. When the limb is elevated, the

arterial pressure falls and the venocapillary bed empties and makes roomfor fresh blood.

This elevation and lowering of the limb is done concurrently with theapplication of the venous constriction and is conveniently effected bymeans of a cradle 22 hung from a davit-like support 23 carried by thecabinet and raised and lowered by means of a cable or tension member 24upon which a pull is periodically exerted by automatically controlledmechanism contained Within the cabinet.

Preferably a reversible electric motor 25 actuates a drum 26 to wind upa tape 2'! attached to the cable for elevating the limb, and actuatesthe drum in the opposite direction to lower the same. The operation ofthe motor 25 is controlled from switches contained within the housing ISin the manner well known; and to insure the motor stopping at the properpositions, an electromagnetic brake 28 of conventional design isoperable upon the motor shaft.

The cradle 22 preferably also incorporates a housing 29 into which thepatients leg projects, as illustrated, and which is heated in anysuitable manner to a desired temperature so that the benefit of localheat application is also made available.

While, as stated, it is desirable to have the lifting and lowering ofthe limb concurrent with the venous constriction, it will be readilyapparent that the automatic mechanism for lifting and lowering the limbmay be utilized as an exerciser independent of venous constriction.

From the foregoing description taken in connection with the accompanyingdrawing, it will be readily apparent to those skilled in the art thatthis invention. provides an entirely safe manner of effecting venousconstriction of a patients limb with readily variable pressures and atcontrollable time intervals particularly adapted to the pati ntsindividual needs; and that the apparatus is extremely simple inconstruction and operation and does not require the presence of skilledtechnicians so that the device lends itself well to home treatment.

What I claim as my invention is:

1. In an instrumentality for treating peripheral vascular diseases byintermittent venous hyperemia: an inflatable cuff adapted to be appliedabout a limb to be treated and operable upon inflation to apply a venouscompression on the limb; a pressure cylinder; means connecting the lowerportion of the pressure cylinder with the cuff so that air expelled fromthe cylinder through said means inflates the cuff; a weighted pistonreciprocable in the cylinder and operable to expel the air therefrom toinflate the cuff to a predetermined pressure positively limited by theweight of the piston; and automatic means for periodically elevating thepiston and releasing it for gravitational descent.

2. In an instrumentality for treating peripheral vascular diseases byintermittent venous hyp-eremia: an inflatable cuff adapted to be appliedabout a limb to be treated and operable upon inflation to apply a venouscompression on the limb; a pressure cylinder; means connecting the lowerportion of the pressure cylinder with the cuff so that air expelled fromthe cylinder through said means inflates the cuff; a weighted pistonreciprocabie in the cylinder and operable to expel the air therefrom toinflate the cuff to a predetermined pressure positively limited by theWeight of the piston; electrically driven means for periodicallyelevating the piston and releasing the same for gravitational descent;and a timed control for said electrical means adjustable to enablevariation of the duration of the pressure period and the frequency ofthe cycles.

3. In an instrumentality for treating peripheral vascular diseases:means for periodically producing a positively limited pressurecomprising, a cylinder, a piston reciprocable therein and movable bygravity in its compression stroke; electric motor driven means forperiodically retracting the piston and releasing it for gravitationaldescent; and an adjustable time switch for regulating the operation ofthe motor so that the frequency of the periodic pressure pulsations andtheir duration is adjustable.

l. An instrumentality for treating peripheral vascular diseases and thelike comprising: a portable supporting structure and a pressure cylindercarried thereby; a weighted piston reciprocable therein and movable inits compression stroke by gravity; electric motor driven means forperiodically retracting the piston and releasing it for gravitationaldescent carried by said portable supporting structure; and means alsocarried by the portable supporting structure for intermittentlyelevating a limb to be treated in predetermined relation to the pressurestrokes of the piston.

5. An instrumentality of the character described comprising: a portablecabinet; an upright air cylinder therein; a duct leading from the lowerportion of the cylinder to the exterior of the cabinet; a weightedpiston slidable in the cylinder and movable by gravity in itscompression stroke; electric motor driven means within the cabinet forperiodically retracting the piston and releasing it for gravitationaldescent; an overhanging elevated support carried by the cabinet; meansincluding a flexible tension member supported from said overhangingsupport for elevating a patients limb; electric motor driven meansinside the cabinet for periodically applying a pull on said tensionelement; and adjustable time switchesfor automatically controlling theoperation of said two electric motor driven means.

FERDINAND J. ROENSCH.

